Stainless is harder than bronze so you want to sharpen like you would with steel. Use kerosene or other thin oil for bronze and water to cool when cutting stainless. A slow cutting speed for both work better but you will not have the heat issue with bronze as you do with stainless. With stainless it is critical you do not let the bit get hot or you will lose your cutting edge in an instant. A steady flow of water will keep your bit cool. I use a squire bottle and just go slow. Bronze is not such a problem.

I am thinking of making my own Silicon Bronze chain plates. Was doing so research and one comment I saw was it is better to punch the holes rather than drill them, as a drilled hole can cause a stress riser. Do you think drilling and causing a stress riser at the hole is a major issue? The hole where turn buckel connects to chain plate would be stressed the most I would think.